The efficacy and toxicity of daily, oral cyclosporin A (CSA) in patients with severe, treatment-refractory rheumatoid arthritis is being evaluated in a 6 month double-blind study of low dose (lmg/kg/day) versus high dose (lOmg/kg/day) CSA. Patients with a 40%, or greater, improvement in disease activity following 6 months of drug therapy are given the option to continue CSA for an additional 6 months. The effects of CSA on various measures of T lymphocyte function in peripheral blood is being investigated. During the past year, analysis of pharmacokinetic studies and immunologic effects of CSA and the 12 months clinical trial have been completed and presented at scientific meetings. The manuscript detailing the clinical results of the trial has been completed and accepted for publication.